Circuit breaker



March 17, 1925.

W. HOOPES CIRCUIT BREAKER Filed Oct. 4, 1922 2 Sheets-Sheet 1 March I7,1925.

W. HOOPES CIRCUIT BREAKER Filed Oct. 4. 1922 2 Sheets-Sheet 2 .ff/ffPatented- Mar. 17, 1925.

PATENT OFFICE.v

WILLIAM HOOPES, F PITTSBURGH, PENNSYLVANIA,

JOHN A. EMERY, n xEcUTon or SAID WILLIAM HOOPES, DECEASED.

CIRCUIT BREAKER. f

Application led October 4, 1922. Serial No. 592,591. I

l To all lwhom z't may concern:

mlof

- lpacity and long lines connected to Be it known that I, WILLIAMHoorns, a citizen of the United States, and a resident of Pittsburgh, inthe county of Allegheny and State of Pennsylvania, have invented a newand useful Improvement in Circuit Breakers, of which'the following is aspecilication.

The invention relates to circuit breakers or interrupting high voltagecircuits, for example those of 10,000 volts and upwards. Such circuits,having high generatlng cal them, are difficult to interrupt withoutgenerating large and destructive amounts of energy at the point ofinterruption, and occasionally the circuit breakers now used fail toopen the circuits and the resulting sustained arcs damage the circuitbreakers and the buildings and equipment surrounding and connected tothem. The usual form of circuit breakers now used forinterrupting 1 highvoltage circuits includes spring-actuated contactors immersed in largebodies of oil which serve the double purpose of cooling andextinguishing any arc which may be formed when the circuit is broken andof reducing the length of the break necessary to be made in ordertointerrupt the circuit. Because of their size and of the rathercomplicated mechanism used for moving the contactors, these circuitbreakers are expensive to manufacture as well as to maintain.

The object of this invention is to provide a circuit breaker which maybe manufactured at much less expense than those now usually used, andwhich is certain in its action. A further object is to provide a circuitbreaker in which a small body of oil may be properly directed to quicklyextinguish an arc as the contactors separate from each other. A stillfurther object is to provide a circuit breaker so constructed that itsoperating parts may be. readily accessible for cleaning, repair andrenewal.

The invention is illustrated in the accompanying drawings of which Fig.1 is an elevation of a single unit of the circuit breaker suspended froma support; Fig. 2 a vertical longitudinal sectional view to enlargedscale taken on the line II-II, Fig. l; and Fig. 3 a view correspondingto the lower portion of Fig. 2 illustrating a modification ofconstruction.

In the practice of the invention the circuit breaking contactors arecaused to move at high speed with relation to each other at the time acircuit is broken, and a stream of oil is directed at high velocitybetween and-transversely to the contactors as they separate from eachother. While in its broader aspects the invention contemplates the useof various mechanism for moving one contactor with relation to anotherfor breaking a circuit, the movement is preferably effected by fluidpressure mechanism. The small body of oil required for quenching an arcin the manner explained may be held inthe bottom of a reservoir fromwhich there may project upwardly the fluid pressure mechanism :foroperating the circuit breaker. This mechanism preferably takes the formof a cylinder containing a movable circuit make-and-break memberincluding a piston. lThe pressurefluid for acting upon the piston tomove such member may be a suitable gas stored under pressure in theupper portion of the reservoir, the expansive force of the gas beingeffective both to move the movable member and to cause the bod of oil toliow between the contactors as they separate.

The invention may be further understood, and other features of itexplained, by reference to the embodiment illustrated in Fig. 2. The oiland compressed gas reservoir may have a substantially conical side wall1, a top 2 and bottom 3, the top and bottom being provided centrallywith openings. Projecting in part upwardly from the top of thereservoir, and in part through the openings in its top and bottom, there4is the cylinder enclosing the movable make-and-break member. Thecylinder preferably includes an intermediate portion 4. formed ofinsulating material, and end tubular portions 5 and 6 formed of electricconducting material. The lower conducting tube 5 may be attached to, orbe formed integrally with a plate 7 which may be attached to the bottom3 of the reservoir by means of machine bolts 8. The intermediate ortion4 of the cylinder may have threade engafvement at its lower end with acentra 1y flanged lplate 9 which may be attached to the top 2 of thereservoir by bolts 10. For attaching the upper conducting tube 6 to theend of the intermediate cylinder section 4, tube 6 may be provided witha iiange 1l bolted to a flange ring 12 having screw thread engagementwith the section 4.

The movable make-and-break member 1n the cylinder includes a ian edpiston 13 arranged to move in the cylin er section 4 and constructed forattachment at its opposite sides to contractors having slidingengagement with the conducting tubes 5 `and 6. The contactor for makingcontact with tube 5 may be a ring 14 attached to the lower end of aconducting tube 15 havlng screw thread engagement at itspupper end withthe lower flange of piston 13, and the upper contactor may take theJform of a rlng 16 attached to a conducting tube 17 secured to the upperiiange of the piston. The upper ortion of contact ring 14 is, as shownin ig. 2, preferably iprovided wlth kerfs so that the ring, in effect,forms a plurallty of contact ngers which yieldingly press outwardlyagainst conducting tube 5. lContact ring 16 may be formed in a similarmanner, except that the outer ends of the ingers are slotted, as at 18,to form gas passages for the purpose presently to be explained.

As stated above, the pressure iluid for moving the movable contactmember to break the circuit is preferably gas stored under pressure inthe reservoir. During the time a circuit is closed through the circuitbreaker, gas under pressure is maintained in the oil reservoir above thesmall body of oil, and in cylinder 4, 5, 6 both above and below thepiston. For this purpose the cylinder containing the movable member isplaced in communication with a source of gas under pressure, and meansare provided to the end that when communication with such source isinterrupted, pressure may be quickly relieved from the top of piston 13,so that the gas stored under pressure below the piston and 1n thereservoir may act upon the lower side of the piston to raise the movablemember.

In the illustrative embodiment of this feature of the invention, the topof contacting tube 6 is provided with a plug 19 forming at its upper enda seat for a relay valve 20 having a small port 21 extending through it.The valve is arranged for vertical sliding movement in a suitable casing22 from which there extends a pipe 23 adapted to be attached to aconduit 24 formed of rubber or other insulating material. Conduit 24leads to a source of gas under pressure (not shown), and flow through itis preferably controlled by three-way valve 25, which in one positionplaces the source of gas pressure in communication with the circuitbreaker, and in its alternate position places the upper end of valve 20in communication with the atmosphere. rl`he relay valve is of theunbalanced pressure type having a larger area at its top than at itsbottom so thatwhen valve 25 places valve 20 in communication with thesource of gas pressure, the same pressure per s uare inch, acting uponthe larger area of t e topthan of thesmaller area. of the bottom of thevalve, will hold the valve against its seat on lug 19.

Valve casing 22 is provided witli ports 26 which serve the doublepurpose of placing the tapered lower side portion of valve 20 incommunication with the atmosphere when the valve is seated, and ofpermitting the free escape of gas from the cylinder when valve 20 isunseated. Gas from the source of supply flowing through port 21 of plug20 flows through large ports 27 formed in plug 19 and from thencethrough the passages 18 formed between the fingers of contactor 16. Tube17 is provided with a small port 28, piston 13 and tube 15 with a smallport 29, and tube 5 with a small port 30 so that gas' may flow in arestricted manner from cylinder 4 into tube 5 below the iston and intothe upper portion of the 011 reservoir.

The upward and downward movements of the movable contact member may bearrested by plungers 31 and 32 arranged within tubular conductors 15 and17, respectively, the former being attached to closure plate 7 and thelatter to plug 19. Attached to side 1 of the oil reservoir by means ofpipes 33 and 34 there may be a gage 35 for indicating the level of oilin the reservoir, and such gage may be provided at its upper and lowerends with removable upper and lower plugs 36 and 37. Oil maybe suppliedto the reservoir by removing upper plug 36, and may be removed from itby removing lower plug 37 To prevent the escape of gas held underpressure in the circuit breaker when the circuit is closed, the severalconnections of the various parts to each other are provided with packingrings or gaskets which may be of the general types illustra-ted, or ofany other suitable form.

The circuit breaker may be placed in an electric circuit by attachingthe closure plate 7 to a conductor 38 by means of a binding post 39,'and by attaching conducting tube 6 to a conductor 40 by means of abinding post 41. Wvhen the circuit breaker is closed, that is topsaywhen the movable member is in the position indicated in Fig. 2, thecircuit is closed between conductors 38 and 40 through closure 7,conducting tube 5, contactor 14, tube 15, piston 13, tube 17, contac-.tor 16 and tube 6.

side of valve 20, this valve is moved upwardly and held in its upwardpos1t1on by the pressure of s on its lower side. The gas ports 27 -in pug 19 and the passages 18- through contactor 16 being large, gas underpressure above piston 13 quickly flows Athrough these ports and passagesand through ports 26 of casing 22 relieving pressure from above piston13. The expansive force of the gas stored in the reservoir above thebody of oil and in tube 5 below the piston acts upon the lower side ofthe piston and causes the movable contact member to move upwardly. Bythe time contactor 14 has moved to the upper end of tube 5A the movablemember acquires a high velocity so that the break effected whencontacter 14 separates from the end of tube 5 is made at high speed.

The pressure of gas upon the top of the body of oil in the reservoirsimultaneously forces the oil through openings 42, which place the lowerend of tube 5 in communication with the oil reservoir, and the oil thusforced into tube 5 is directed between this tube and plunger 31transversely between contactor 14 and the end of tube 5, such How of theoil being through the kerfs in contactor 14. Because of the highpressure on the oil in the reservoir, and because ort 30 is so smallthat gas cannot iow theret irough rapidly enough to prevent it, the oiliiows upwardly in tube 5 as rapidly as the movable member movesupwardly, and therefore remains in contact with contactor 14. As soon ascontactor 14 separates from tube 5 the oil is projected violently acrossthe rapidly increasing break, so that fresh oil is passed at highvelocity across any are that may be formed and serves to reduce thevolume of the arc to small indestructive proportions, the arc beingentirely eX- tinguished as soon as the length of the break is equal tothel puncture distance through the oil at the voltage momentarilyexisting across the break. The moving contact member continues itsupward movement in the cylinder until near the end of its permissiblerange of travel, where it is arrested by an air cushion formed in thelower end of tube 17 below the end of plunger 32, the air being able toescape but slowly through port 28 in the lower end of tube 17.

The moving contact member is maintained in its upper position by reasonof the outward pressure Iof the lingers of contactor 16 against tube 6.Therefore the movable contact member does not drop back to close theswitch until after the circuit breaker is again placed in communicationwith the source of gas supply. l/Vhen the movable contact member hasreached its upper position the gas under pressure in the reservoirgradually leaks out through the several ports which place it incommunication with the atmosphere, at which time the circuit breaker maybe again closed. The circuit breaker shown particularly in Fig. 2 isintended only to break a circuit, there being illustrated in Fig. 3 amodified form of circuit breaker which may be used both to open andclose the circuit. In closing a circuit which has been opened by thecircuit breaker of Fig. 2, the actual closure of the circuit is made bymeans of an air disconnecting switch of any suitable or well knownconstruction, before which the circuit breaker shall have been closed byturning the three-way valve 25 to`the position in which it places the-circuit breaker in communication with the source of gas sup- When it isdesired to examine the movable contact member or to clean or repair it,the small body of oil in the bottom of the reservoir may be withdrawnafter removing plug 37 from the bottom of gage Thereafter closure plate7, together with contact tube 5, may be removed, and the contact membertaken out of its cylinder by moving it downwardly through the opening inbottom 3 of the reservoir.

As previously stated, the circuit breaker illustrated in Fig. 3 isintended to be used both for breaking and making the circuit. It differsfrom the circuit breaker of Fig. 2 chiefly in that the bottom of the oilreservoir is provided with a well 43 so that the upper end of contacttube 5 may at all times be immersed in oil. The insulating tube 4* iscontinued downwardly below the top 2a of the oil reservoir to a shortdistance below the top of conducting tube 5, and tubular conductor 15may have an enlarged solid upper portion 44, or be otherwise formed sothat the lower arresting plunger 31a cooperates with tubular conductor15a to act as a dash-pot to arrest the downward movement of the movableContact member when the circuit is being closed.

The compressed gas used for operating the circuit breaker may be air,although it is preferred to use a gas which does not form an explosivemixture with oil vapor. Where there are suflicient circuit breakersinstalled to justify it, nitrogen, obtained from small air distillationapparatus and stored under proper pressure, is preferably used. Vlierethe number of circuit breakers installed is not large enough to justifythe expense of such a nitrogen plant, carbonio acid gas derived fromliquid carbonio acid may be used. Both nitrogen and carbonio acid gasobtained in these ways.are dry, and when they are used there is nodanger from freezing of moisture within the circuit breaker, orcontamination of the oil by moisture. In case air is used it should bethoroughly dried.

While a single circuit breaker may be used to break each pole of acircuit, preferably two units are arranged in series for each pole, thusreadily adaptingthe circuit breaker for use with the usual switchingstation construction. A bus bar 45 (Fig.l l) or other conductor, may beused to electrically connect two circuit breakingfunits, and a singlethree-Way valve 25 may place the two units in communication with thesource of gas under pressure, there being two conduits 24a leading fromthe threeway valve. The number of branch pipes 24* leading from valve 25will ofcourse be multiplied in proportion to the number of unitscontrolled. The circuit breakers maybe suspendedfrom a suitablestructural support 46 b means of a series of insulators 47, an whenVused out of doors the exterior surface of insulating cylinder 4 may beprovided with insulating petticoats in any well known manner.

According to the provisions of the patent statutes, I have described theprinciple and operation of my invention together with what I nowconsider to be the best structural embodiment thereof, howeverI desireto have it'understood that, within the scope of the appended claims, theinvention may be practiced by other forms of construction than thatspecifically shown and described.

I claim:

1.4 A circuit breaker comprisinga pair of electric conducting elementsadapted to contact with each other to close a circuit, means for movingone of said elements with relation to the other to break the circuit, areservoir provided with a body of oil in communication with saidelements, means for maintaining a body of gas under pressure above saidoil, and means for'utilizing the expansive force of lsaid gas to' directa stream of said oil between said elements as the movable separates fromthe xed element.A l

2. A circuit breaker, comprising a fixed and a movableelectric-conducting contacting element, a reservoir provided with a bodyof oil in communication with said elements, means for maintaining a bodyof gas under pressure above said oil, and means for uti- 'lizing theexpansive force of said gas to reciprocable in said tube and contactingtherewith, means for maintaining a body of gas under pressure above theoil in said reservoir, and means for utilizing the expansive -forceVo'f'said gas to move said re-l ciprocable conductor beyond the end ofsaid tube and to direct a stream of oil between said conductors as theyseparate.

4.*In a circuit breaker, an oil reservoir, a fixed conductor therein, amovable contactor. for completing a circuit through said conductor, oHuid pressure actuated means for movingrsaid contactor to break theVcircuits, and means e'ectiveupon the movement of said contactor todirect a stream of oil fron'isaid reservoir between said conductorandcontactor as the latter separates from the former.

V5. In a circuit breaker, the combination of an 011 reservoir, a fixedconductor therein, a movable contactor for closing a circuit y piston 1nsaid cylinder attached to said contactor, means for maintaining gasunder pressure in said reservoir and on the upper and lower sides ofsaid piston, said piston upon the removal of pressure from the gas onits upper side being movable by the expansive force of the gas in thereservoir to cause said contactor to break contact with said conductor.

6. In a circuit breaker, the combination of an oil reservoir, a fixedconductor therein, a movable contactor for closing a circuit throughsaid conductor, a cylinder communicating at one end with Asaidreservoir, a piston in said cylindenattached to said contactor, meansfor maintaining gas under pressure in said'reservoir and on the upperand lower sides of said piston, said piston upon the removal ofvpressure from the gas on its upper side being movable by the expansiveforce ofthe gas in the reservoir to cause said contactor to breakcontact with said conductor-and means for `utilizing the expansive forceof the gas in the reservoir to direct a, stream of oil from thereservoir between the conductor and contactor as they separate.

7. In a circuit breaker, the combination of an oil reservoir, anelectric conducting tube projecting upwardly from and communicating withthe bottom of the reservoir, a cylinder in alignment with saidvtube andhaving a piston therein, a contact ring attached to said piston andcontacting with the inner wall of the tube to close a circuit, means formaintaining gas under pressure in said reservoir and above said piston,said piston upon the removal of pressure from the gas on its upper sidebeing movable by the expansive force of the gas in said reservoir tocause said contactor to move beyond said tube to break'the circuit, andthe eX- pansive force of the gas in said reservoir being simultaneouslyeffective to project oil from said reservoir upwardly through said tubeand in a stream between the uplper end of the tube and contact ring whent e latter separates from the former.

8. In a circuit breaker, an oil reservoir,- a cylinder extendingupwardly from the ieservoir and comprising an intermediate tube ofinsulating material and upper and lower electric conducting tubes, aapted to be electrically connected to a circuit, a movable electricconducting member in said cylinder for closing the circuit through saidconducting tubes and comprising a piston in the intermediate tube andcontactors attached one to each side of the piston and having slidingcontact with said 'conducting tubes, and means for applying fluidpressure to the lower side of said piston `to move said movable memberupwardly and thereby -cause the lower contactor to break Contact withthe lower conducting tube.

9. In a circuit breaker, an oil reservoir having an opening in itsbottomclosed by a removable closure, a cylinder extending upwardly from saidclosure and comprising an intermediate tube of insulating material andupper and lower electric conducting tubes adapted to be electricallyconnected to a circuit, and a movable circuit make-and-break member insaid cylinder including contactors adapted to contact with saidconducting tubes, said movable inember being removable from the cylinderthrough said opening in the bottom of the reservoir.

10. In a circuit breaker, anoil reservoir, a cylinder extending upwardlyfrom; the reservoir and comprising an intermediate tube of insulatingmaterial and uiper and lower elect-ric conducting tubes, a apted to beelectrically connected to a circuit, a movable electric conductingmember in said cylinder for closing the circuit throughsaid conductingtubes and comprising a piston in the intermediate tube and contactorsattached one to each side of the iston and having sliding contact withsai conducting tubes, said piston having a small gas port through it,and means for placing the upper end of said .cylinder in communicationwith a source of gas under pressure, whereby gas flows through saidpiston port into said cylinder and becomes effective to move said pistonto break the circuit when communication with said source of gas is cutoff.

11. In a circuit breaker, an oil reservoir, a cylinder extendingupwardly from the reservoir and comprising an intermediate tube ofinsulating material and upper and lower electric conducting tubesadapted to be electrically connected to a circuit, a movable electricconducting member in said cylinder for closing the circuit through saidconducting tubes and comprising a piston in the intermediate tube andcontactors attached one to each side of the piston and havingslidingContact with said conducting tubes, said piston-having a small gas portthrough it, a relay valve at the to of said cylinder, and a conduitextending om said valve to a source of gas under pressure, said conduitbeing provided with a valve for alternately placing said relay valve incommunication with the source of gas supply and with the atmosphere.

12. In a circuit breaker, an oil reservoir,

a cylinder extending upwardly from the reservoir and comprising anintermediate tube of insulating material and u per and lower electricconducting tubes adbpted to be electrically connected to a circuit, amovable electric conducting member in said cylinder for closing thecircuit through said conducting tubes and comprisin a piston in theintermediate tube and tuular electric conductors attached to andextending one from each side of the piston, said tubular conductorsbeing provided with contact rings making sliding Contact with saidconducting tubes, rods arranged in said tubular conductors for guidingand cushioning the movements of said movable member, and means forapplying fluid pressure to the lower side of said piston to break thecircuit.

- 13. In a circuit breaker, the combination of a pair of electricconducting elements adapted to contact with each other to close acircuit, a fluid pressure mechanism including a piston for moving one ofsaid elements with relation to the other for breaking the circuit, meansincluding a. control valve for normally maintaining ressure fluid onboth sides of said piston, an a relay valve for quickly releasing thepressure iiuid on one side of said piston when the control valve ismoved to operate the circuit breaker.

14. In a circuit breaker, the combination of an oil reservoir, a fixedconductor, amovable contactor for closing a circuit through saidconductor, a cylinder communicating at one end with said reservoir apiston in Isaid cylinder attached to said contactor,

Ameans including a control valve for maintaining gas under pressure insaid reservoir and on the upper and lower sides of said piston, and arelay valve for quickly releasing the pressure fluid on the upper sideof said piston when the control valve is moved to operate the circuitbreaker.

15. In a circuit breaker, an oil reservoir, a cylinder extendingupwardly from the reservoir, and comprising an intermediate tube ofinsulating-material and upper and lower electric conducting tubesadapted to be held connected to a circuit, a movable electric conductingmember in said cylinder for closing the circuit through said conductingtubes and comprising a piston in the interlll mediate tube andoontaotors attached one fected tonquickl release the pressure iuid 10 toeach side of the Piston and havin slid# on the up r si e of said pistonwhen said ing contact with said conducting` tu s, -a control va ve ismoved to close communicaby-pass of constricted area to permit the tionbetween the circuit breaker and source [passage of gas past sald piston,a. relay of gas supply. A .e

valve at thetop of said e linder, and a eon- In testimony whereof Islisn m name. duit including a contro valve extending WILLIA H OPES.from said relayvalve to a source of gas Witness: under pressure, saidrelay valve being ef- EDWIN 0. JOHNS.V

